1. Technical Field
The present disclosure relates to a stator coil forming method for a motor.
2. Description of Related Art
There has been known a stator coil forming method in which U-shaped lead wires are assembled to respective slots of a stator core, and distal ends of the lead wires are tilted in a circumferential direction of the stator core and then twisted, so that coil-end end surfaces of coil segments are formed horizontally relative to an axial end surface of the stator core, thereby forming coil ends which are reduced in a volume in a stator-core axial direction and which have no straight part (see Japanese Patent Application Publication No. 2006-304507 (JP 2006-304507 A)).
In the stator coil forming method, the coil ends are inserted into a groove of a toric jig and the toric jig is moved up and down while being rotated, so that the coil ends are deformed plastically while being tilted in the circumferential direction of the stator core. By this process, the coil ends that have no straight part are formed. However, referring to FIG. 13, when coil ends 201 are tilted in a circumferential direction of a stator core 202, it is necessary to secure an insulation distance between distal ends 203 adjacent to each other in the circumferential direction (side faces of the distal ends 203 of the coil ends 201 adjacent to each other in the circumferential direction, the side faces being opposed to each other). For example, like a circled part in FIG. 13, the distal end 203 is cut diagonally. Because of this, a cut margin of the lead wire is wasted, which causes a poor yield. Further, in this case, a distance between the coil ends 201 adjacent to each other in the circumferential direction is shortened, so welded parts of the coil ends 201 come closer to each other in the circumferential direction. In the welded parts, an insulating coating is removed. This further increases waste of material.